4-phenoxycoumarins as herbicidal agents

ABSTRACT

There are provided methods to control mono-cotyledenous weed species in the presence of crops and particularly in the presence of cereal crops. Also provided are 4-(2,6-disubstituted-phenoxy)coumarin derivatives useful as herbicidal agents and methods to prepare same.

This is a continuation-in-part of application Ser. No. 08/279,579, filedon Jul. 25, 1994 now U.S. Pat. No. 5,563,280.

BACKGROUND OF THE INVENTION

The selective control of weeds is a constant problem in crop productionaround the world. In particular the control of monocotyledenous weedswhen growing in the presence of monocotyledenous crops such as cerealcrops is burdensome. Not only do said weed species tend to proliferateunder the same or similar cultivation conditions in which cereal cropsflourish, but in addition, the very herbicidal agents which are mosteffective for controlling these weeds, also tend to cause harmfulphytotoxic effects to cereal crop plants. Therefore, new effectivemethods for the selective control of unwanted monocotyledenous weeds incereal crop production are continually sought.

It is an object of this invention to provide methods for the effectivecontrol of monocotyledenous weeds in the presence of crop plants,including monocotyledenous crop plants, without undue harm to said cropplants.

It is a further object of this invention to provide4-(2,6-disubstituted-phenoxy)coumarin derivatives, useful as selectiveherbicides in crop production and particularly in cereal cropproduction.

It is an advantage of this invention that the4-(2,6-disubstituted-phenoxy)coumarin derivatives are particularlyeffective for controlling grass and other monocotyledenous weeds underflooded paddy rice application conditions while having little or nophytotoxic effects on the rice crop.

SUMMARY OF THE INVENTION

The present invention relates to a method for the control ofmonocotyledenous annual, perennial and aquatic plant species whichcomprises applying to the soil or water containing the seeds or otherpropagating organs of said plant species a herbicidally effective amountof a compound of formula I ##STR1## wherein X and X' are eachindependently halogen, C₁ -C₄ alkyl or C₂ -C₄ alkenyl;

W, Y and Z are each independently O or S;

R is any combination of from one to three H, halogen, C₁ -C₄ alkyl, C₃-C₆ cycloalkyl, C₁ -C₄ haloalkyl or C₁ -C₄ alkoxy groups;

R₁ is any combination of from one to four H, halogen, OH, CN, NO₂, SH,C₁ -C₆ alkyl optionally substituted with one or more halogen or OR₂groups, C₃ -C₆ cycloalkyl, C₁ -C₆ alkylthio, C₂ -C₆ alkenyl, C₂ -C₆halo-alkenyl, C₂ -C₆ alkynyl, C₂ -C₆ haloalkynyl, OR₂, OCH₂ COOR₃, OCH₂OR₄, OCOOR₅, OCONHR₆, OCOR₇, S(O)_(n) R₈, COR₉, CH(OR₁₀)₂, phenyloptionally substituted with one to three halogen, CN, C₁ -C₄ alkyl, C₁-C₄ haloalkyl, C₁ -C₄ alkoxy or C₁ -C₄ haloalkoxy groups, or benzyloptionally substituted with one to three halogen, CN, C₁ -C₄ alkyl, C₁-C₄ haloalkyl or C₁ -C₄ alkoxy groups;

R₂ is H, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl,C₂ -C₆ haloalkenyl or C₂ -C₆ haloalkynyl;

R₃, R₄, R₅, R₆ and R₇ are each independently H, C₁ -C₄ alkyl, C₁ -C₄haloalkyl, C₃ -C₆ cycloalkyl, phenyl optionally substituted with one tothree halogen, CN, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy or C₁-C₄ haloalkoxy groups, or benzyl optionally substituted with one tothree halogen, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl or C₁ -C₄ alkoxy groups;

R₈ is C₁ -C₄ alkyl, C₁ -C₄ haloalkyl or phenyl optionally substitutedwith one to three halogen, CN, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄alkoxy or C₁ -C₄ haloalkoxy groups;

R₉ is H, OH, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenyl optionally substitutedwith one to three halogen, CN, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄alkoxy or C₁ -C₄ haloalkoxy groups, benzyl optionally substituted withone to three halogen, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy orC₁ -C₄ haloalkoxy groups or NR₁₁ R₁₂ ;

R₁₀ is H, C₁ -C₄ alkyl or --(CH₂)_(m) --; R₁₁ and R₁₂ are eachindependently H, C₁ -C₄ alkyl, C₂ -C₄ alkenyl or R₁₁ and R₁₂ may betaken together with the atoms to=which they are attached to form a 5- or6-membered ring optionally interrupted by oxygen;

n is an integer of 0, 1 or 2 and

m is an integer of 2 or 3.

The invention also relates to the selective control of monocotyledenousweed species in the presence of crops which comprises applying to thesoil or water in which the seeds or propagating organs of the weedspecies are located and in which the crop has been planted ortransplanted a herbicidally effective amount of a compound of formula Ias described hereinabove.

The invention further relates to herbicidal compounds of formula I,compositions containing same, and a method to prepare said compounds.

DETAILED DESCRIPTION OF THE INVENTION

Crop production can be reduced by as much as 30% to 60% by the presenceof persistent and pestiferous weed species. A particular weed problem inraising and harvesting a variety of crops, particularly cereal crops, ismonocotyledenous weed species such as monochoria, saggitaria, sedges andgrasses. This is a persistent problem in the production of cereals suchas corn, wheat, barley, rice, rye and the like. Most particularly, thepresence and proliferation of grass weeds such as barnyardgrass andwatergrass in rice cultivation can significantly lower crop yields andquality. The problem is further complicated because, in general, thoseagents which control monocotyledenous plants inherently cause phytotoxicdamage to cereal crops.

It has now been found that monocotyledenous, annual, perennial andaquatic, weed species such as monochoria, saggitaria, sedges and grassesare effectively controlled by the application of 4-phenoxycoumarinderivatives of formula I to the soil or water in which the seeds orpropagating organs are located.

Surprisingly, said monocotyledenous weeds may be selectively controlledin the presence of cereal crops such as corn, wheat, barley, rice, ryeand the like with little or no phytotoxic injury to said crops.Advantageously, 4-phenoxycoumarins of formula I may Re appliedpreemergence to the monocotyledenous weeds and post-transplant to therice crop seedlings under flooded paddy conditions to give effectiveweed control with little or no commensurate injury to the rice cropplants.

The 4-phenoxycoumarin derivatives of the invention which are useful asherbicidal agents are those compounds of formula I ##STR2## wherein Xand X' are each independently halogen, C₁ -C₄ alkyl or C₂ -C₄ alkenyl;

W, Y and Z are each independently O or S;

R is any combination of from one to three H, halogen, C₁ -C₄ alkyl, C₁-C₆ alkylthio, C₃ -C₆ cycloalkyl, C₁ -C₄ haloalkyl or C₁ -C₄ alkoxygroups;

R₁ is any combination of from one to four H, halogen, OH, CN, NO₂, SH,C₁ -C₆ alkyl optionally substituted with one or more halogen or OR₂groups, C₃ -C₆ cycloalkyl, C₁ -C₆ alkylthio, C₂ -C₆ alkenyl, C₂ -C₆haloalkenyl, C₂ -C₆ alkynyl, C₂ -C₆ haloalkynyl, OR₂, OCH₂ COOR₃, OCH₂OR₄, OCOOR₅, OCONHR₆, OCOR₇, S(O)_(n) R₈, COR₉, CH(OR₁₀)₂, phenyloptionally substituted with one to three halogen, CN, C₁ -C₄ alkyl, C₁-C₄ haloalkyl, C₁ -C₄ alkoxy or C₁ -C₄ haloalkoxy groups, or benzyloptionally substituted with one to three halogen, CN, C₁ -C₄ alkyl, C₁-C₄ haloalkyl or C₁ -C₄ alkoxy groups;

R₂ is H, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl,C₂ -C₆ haloalkenyl or C₂ -C₆ haloalkynyl;

R₃, R₄, R₅, R₆ and R₇ are each independently H, C₁ -C₄ alkyl, C₁ -C₄haloalkyl, C₃ -C₆ cycloalkyl, phenyl optionally substituted with one tothree halogen, CN, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy or C₁-C₄ haloalkoxy groups, or benzyl optionally substituted with one tothree halogen, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl or C₁ -C₄ alkoxy groups;

R₈ is C₁ -C₄ alkyl, C₁ -C₄ haloalkyl or phenyl optionally substitutedwith one to three halogen, CN, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄alkoxy or C₁ -C₄ haloalkoxy groups;

R₉ is H, OH, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenyl optionally substitutedwith one to three halogen, CN, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄alkoxy or C₁ -C₄ haloalkoxy groups, benzyl optionally substituted withone to three halogen, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy orC₁ -C₄ haloalkoxy groups or NR₁₁ R₁₂ ;

R₁₀ is H, C₁ -C₄ alkyl or --(CH₂)m--;

R₁₁ and R₁₂ are each independently H, C₁ -C₄ alkyl, C₂ -C₄ alkenyl orR₁₁ and R₁₂ may be taken together with the atoms to which they areattached to form a 5- or 6-membered ring optionally interrupted byoxygen;

n is an integer of 0, 1 or 2 and

m is an integer of 2 or 3.

It is understood that R and R₁ represent substituents on the phenyl ringin positions 3, 4 and 5 (in the case of R) and on the fused benzene ringin positions 5, 6, 7 and 8 (in the case of R₁). In each instance thearomatic ring may range from being fully substituted to being fullyunsubstituted (in the case of R₁) or disubstituted by X and X' (in thecase of R). When the phenyl ring is disubstituted with X and X', then Ris designated H. When the fused benzene ring position of the4-phenoxycoumarin of formula I is fully unsubstituted, then R₁ isdesignated H.

The term haloalkyl designates an alkyl group, C_(n) H_(2n+1), containingfrom one halogen atom to 2n+1 halogen atoms. Halogen atoms are Cl, Br, For I.

Preferred compounds of formula I are those wherein X and X' are eachindependently Cl, Br, or CH₃ and W, Y and Z are O. More preferredcompounds are those wherein X and X' are each independently Cl, Br orCH₃ ; W, Y and Z are O; R is H and R₁ is one, two or three halogen, C₁-C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy, C₁ -C₄ haloalkoxy or NO₂groups. Particularly preferred compounds are those wherein X and X' areeach independently Cl, Br or CH₃ ; W, Y and Z are O; R is H and R₁ is5-C₁ -C₄ alkyl, 5-halogen, 5-C₁ -C₄ haloalkyl or 5-NO₂.

The 4-(2,6-disubstituted-phenoxy)coumarin compounds of formula I may beprepared from readily available 2-hydroxyacetophenones of formula III ortheir salicylic acid precursors of formula II. The formula II acid maybe converted to the corresponding acetophenone of formula III in thepresence of methyl lithium using standard literature procedures such asthat described by Heimark et al in the Journal of Labelled Compounds andRadiopharmaceuticals, 1986, Vol. 23, No. 2. The formula III acetophenonemay be reacted with ethyl carbonate in the presence of at least 2 molarequivalents of a base such as sodium hydride to give the4-hydroxycoumarin of formula IV. Said hydroxycoumarin may then beconverted to the corresponding 4-chlorocoumarin derivative of formula V,using standard procedures such as POCl₃ plus an amine scavenger. Theformula V chlorocoumarin is then reacted with a 2,6-disubstituted-phenolor thiophenol of formula VI to give the desired formula I productwherein Y is oxygen (formula Ia). To obtain those formula I productswherein Y is sulfur (Ib), the coumarin of Ia may be reacted withLawesson's reagent or P₂ S₅. The reaction scheme is shown in FlowDiagram I. ##STR3##

Alternatively, the formula II salicylic acid may be converted to thecorresponding formula VII acid chloride. The acid chloride may betreated with ethyl malonate in the presence of a base as described inJournal of Medicinal Chemistry, 1975, Vol. 18, No. 4, pp. 391-394 by D.R. Buckle et al, to form an intermediate which is decarboxethoxylated byheating, optionally in the presence of a solvent, to afford the desired4-hydroxycoumarin of formula IV. The formula IV hydroxycoumarin may beconverted to 4-(2,6-disubstituted-phenoxy)coumarin compounds of formulaI as shown hereinabove in Flow Diagram I. The reaction sequence isillustrated in Flow Diagram II. ##STR4##

The 4-(2,6-disubstituted phenoxy)coumarin herbicidal agents of formula Imay also be effectively prepared from phenols of formula VIII bytreatment with dimethyl acetylenedicarboxylate as described by H.Cairns, et al in the Journal of Medicinal Chemistry, 1972, Vol. 15, No.6, pp. 583-589, to give the formula IX fumaric acid. Surprisingly,treatment of the formula IX fumaric acid with a mixture of phosphorouspentoxide and methane sulfonic acid affords the formula Xchromone-2-carboxylic acid in high yield. The formula X intermediate maythen be converted to the formula V chlorocoumarin by treatment withthionyl chloride in the presence of a catalytic amount of dimethylformamide as described by V. A. Zagorevskii and E. K. Orlova in ZhurnalObschei Khimii, Vol. 33, No. 6, 1963, pp. 1857-1863. The thus-prepared4-chlorocoumarin may be employed to give the desired4-(2,6-disubstituted phenoxy)coumarins of formula I as describedhereinabove in Flow Diagram I. The reaction sequence is illustrated inFlow Diagram III. ##STR5##

The 4-phenoxycoumarin compounds of the present invention are thosecompounds of formula I wherein X, X', W, Y, R and R₁ are as describedhereinabove with the proviso that at least one of R₁ must be other thanH. Said compounds are effective herbicidal agents useful for the controlof a variety of monocotyledenous annual and perennial weed species.Moreover, these compounds are effective for the control of weedsindigenous to both dry land and wet land areas. Effective control may beobtained with application rates of about 0.006 kg/ha to 4.0 kg/ha,preferably about 0.06 kg/ha to 2.0 kg/ha. It is, of course, clear thatrates above 4.0 kg/ha may be used to effectively control undesirablemonocotyledenous weed species; however, rates of application ofherbicide above the required effective level should be avoided sinceapplication of excessive amounts of herbicide is costly and serves nouseful function in the environment.

Surprisingly, it has been found that the formula I phenoxycoumarincompounds of the invention are selective herbicides, useful in cropproduction. In particular, the formula I compounds are effective forcontrolling pestiferous monocotyledenous weeds such as grasses, sedges,monochoria and saggitaria in the presence of cereal crop plants such ascorn, wheat, rye, barley, rice and the like. More particularly, theformula I compounds are especially valuable for controlling grass weedsin the presence of transplanted rice plants under flooded paddyconditions.

In actual agronomic practice, the compounds of the invention are appliedin the form of a composition comprising an agronomically acceptablesolid or liquid carrier and an herbicidally effective amount of aformula I phenoxycoumarin compound. For example, application may be inthe form of liquid compositions such as suspension concentrates, aqueousconcentrates, emulsifiable concentrates, concentrated emulsions and thelike or in the form of solid compositions such as wettable powders,dispersible granulars, granular formulations, dusts and the like. It iscontemplated the compounds of the invention be applied in combinationwith other pesticides either sequentially or concurrently as a tankmixture or as a single combination composition. In particular thecombination application of a formula I phenoxycoumarin with aco-herbicide such as a sulfamoylurea, sulfonylrea, dinitroaniline,imidazolinone, thiocarbamate, azolopyrimidine sulfonamide,α-haloacetamide and the like. Of particular interest are combinationscomprising a formula I phenoxycoumarin and a sulfamoylurea, adinitroaniline, a sulfonylurea, or an imidazolinone. While not required,the combination composition comprising a formula I compound and acoherbicide may also comprise other components, for example,fertilizers, inert formulation aides such as surfactants, emulsifiers,defoamers, dyes, extenders and the like.

For a more clear understanding of the invention, specific examplesthereof are set forth below. The invention described and claimed hereinis not to be limited in scope by these merely illustrative examples.Indeed, various modifications of the invention in addition to thoseexemplified and described herein will become apparent to those skilledin the art from the following examples and the foregoing description.Such modifications are also intended to fall within the scope of theappended claims. The terms ¹ H, ¹³ C, ¹⁹ FNMR designate proton, carbonand fluorine nuclear magnetic resonance spectroscopy, respectively. IRdesignates infrared spectroscopy and HPLC designates high performanceliquid chromatography.

EXAMPLE 1 Preparation of 2-hydroxy-3-methoxyacetophenone ##STR6##

A mixture of 3-methoxysalicylic acid (4.0 g, 24 mmole) intetrahydrofuran, under nitrogen, is treated dropwise with methyl lithium(56 mL of 1.4M solution in ether, 78.4 mmole) at a rate sufficient tomaintain reflux temperature. The reaction mixture is stirred at refluxtemperature for 17 hours, cooled to room temperature and poured over amixture of brine, ice and 6N HCl. The resultant mixture is extractedwith ethyl acetate. The organic extracts are combined, washed withbrine, dried over Na₂ SO₄ and filtered. The filtrate is concentrated invacuo to give a dark orange residue which is taken up in 1:2 ethylacetate: hexane, filtered through a silica gel plug and reevaporated togive a residue. This residue is crystallized from cyclohexane to givethe title product as yellow needles, 2.08 g (53% yield), mp 49°-51° C.,identified by HPLC, ¹ HNMR and mass spectral analyses.

EXAMPLE 2 Preparation of 8-methoxycoumarin ##STR7##

A stirred mixture of NaH(0.58 g 60% NaH, 14.5 mmole) and ethyl carbonate(2.84 g, 24 mmole) in chloroform, under N₂, is treated dropwise with asolution of 2-hydroxy-3-methoxyacetophenone (0.80 g, 4.8 mmole) inchloroform, heated at reflux temperature for 40 hours, cooled to roomtemperature, treated with about 45 mL 1N NaOH and stirred vigorously for24 h. The phases are separated and the aqueous phase is acidified with6N HCl. The resultant precipitate is filtered, washed with water anddried to give the title product as a white solid, 0.88 g (96% yield),identified by ¹ HNMR analysis.

EXAMPLE 3 Preparation of 4-chloro-6-methoxycoumarin ##STR8##

A stirred mixture of 4-hydroxy-6-methoxycoumarin (116 g, 0.603 mole) andPOCl₃ (462.29 g, 3.015 mole) in toluene is treated dropwise withtri-n-butylamine (250 mL, 1.73 mole) at 25° C., heated at 100°-110° C.and monitored by HPLC analysis. When the reaction is complete, themixture is cooled to room temperature, poured over ice, stirredmechanically for about 2 hours and filtered. The filtercake is washedwith water and toluene, dissolved in methylene chloride and filteredthrough diatomaceous earth. The methylene chloride filtrate isconcentrated and treated with a mixture of dimethylformamide andacetonitrile to afford crystallization. The mixture is filtered to givethe title product, 81.7 g, (64% yield) identified by HPLC analysis.

EXAMPLE 4 Preparation of 4-(2,6-dichlorophenoxy)-6-methoxycoumarin##STR9##

A stirred mixture of 4-chloro-6-methoxycoumarin (1.0 g, 4.75 mmole),2,6-dichlorophenol (0.85 g, 5.22 mmole) and K₂ CO₃ (0.98 g, 7.12 mmole)in acetonitrile, under N₂, is heated at reflux temperature for 16 hours,cooled to room temperature and poured into ice water. This mixture isextracted several times with ether. The extracts are combined andconcentrated in vacuo to give a tan solid residue. The residue iscrystallized from ethyl acetate/hexane to afford the title product astan crystals, 1.17 g (73% yield), mp 170°-171° C., identified by IR, ¹HNMR, ¹³ CNMR, and mass spectral analyses.

EXAMPLE 5 Preparation of 4-(2-6-dichlorophenoxy)-6-hydroxycoumarin##STR10##

A solution of 4-(2,6-dichlorophenoxy)-6-methoxycoumarin (25 g, 0.074mol) in methylene chloride, under N₂, is treated dropwise with 296 mL ofa 1.0M solution of BBr₃ in methylene chloride at -70° C. When additionis complete, the dry ice/acetone cooling is removed and the reaction isallowed to come to room temperature over a 16 hour period. The reactionmixture is diluted with additional methylene chloride, poured into icewater with mechanical stirring and filtered to give a pale yellow solidfiltercake. The solid is air-dried and crystallized fromdimethylformamide/acetonitrile/water (1:1:0.1) to afford the titleproduct as white crystals, 19.7 g (86% yield), mp>250° C. identified by¹ HNMR analysis.

EXAMPLE 6 Preparation of 4-(2,6-dichlorophenoxy)-6-(difluoromethoxy)coumarin ##STR11##

A stirred suspension of 4-(2,6-dichlorophenoxy)-6-hydroxycoumarin (1.3g, 3.71 mmole) in acetone is bubbled through with chlorodifluoromethaneat room temperature, under N₂, for about 30-45 minutes, cooled to 5°-10°C., treated with 50% NaOH solution (2.4 g, 1.2 g NaOH, 29.7 mmole NaOH),stirred for 2 hours at room temperature and filtered. The solidfiltercake is washed with methylene chloride and crystallized fromacetonitrile/methanol/water to afford the title product as a whitesolid, 0.95 g (69% yield), mp 1450°-148° C., identified IR, ¹ HNMR, ¹⁹FNMR, ¹³ CNMR, and mass spectral analyses.

EXAMPLE 7 Preparation of 4-hydroxy-8-nitrocoumarin ##STR12##

A solution of NaH (6.94 g, 0.291 mole) in dimethoxyethane is cooledusing dry ice/acetone cooling, treated dropwise with diethyl malonate(46.6 g, 0.29 mole), allowed to warm to 0° C., treated dropwise with asolution of 3-nitrosalicylyl chloride (19.5 g, 0.10 mole) indimethoxyethane, allowed to warm to room temperature, stirred for 3hours at room temperature, heated at 60° C. until reaction is completeby HPLC analysis, cooled to room temperature, poured onto a mixture ofice water and methylene chloride and stirred for about 0.5 hour. Thephases are separated, the aqueous phase is acidified with 50% HCl to pH5 and filtered. The filtercake is dispersed in acetic acid, heated andfiltered. This filtercake is air-dried and 8.6 g is dispersed indimethyl sulfoxide, heated at 100° C. for about 2 hours, cooled to roomtemperature, poured onto ice water and filtered. The solid is taken upin acetonitrile, filtered hot, cooled and filtered to give the titleproduct, mp 242°-245° C., identified by IR, ¹ HNMR and mass spectralanalyses.

EXAMPLE 8 Preparation of 4-(2,6-dichlorophenoxy)-6-methoxythionocoumarin##STR13##

A mixture of 4-(2,6-dichlorophenoxy)-6-methoxycoumarin (0.40 g, 1.2mmol) and Lawesson's Reagent¹ (0.53 g, 1.3 mmol) in dioxane is heated atreflux temperature, stirred for about 4 hours, cooled to roomtemperature, stirred at room temperature for 16 hours and filtered. Thefiltercake is washed with petroleum ether and air-dried to give thetitle product as a yellow solid, 0.28 g (57% yield), mp 231°-232° C.,identified by ¹ HNMR, ¹³ CNMR and mass spectral analyses.

EXAMPLES 9-15 Preparation of 4-phenoxythionocoumarin derivatives##STR14##

Using essentially the same procedure described in Example 8 andsubstituting the appropriate 4-phenoxycoumarin substrate, the followingcompounds are obtained.

                  TABLE I                                                         ______________________________________                                         ##STR15##                                                                    Example                                                                       No.      X        X'    R       W   R.sub.1                                   ______________________________________                                         9       Cl       Cl    H      O    5-OH                                      10       Br       Br    H      O    7-OCH.sub.3                               11       Cl       Cl    H      O    7-OCH.sub.3                               12       Cl       Cl    H      O    6,7-di-OCH.sub.3                          13       Cl       Cl    H      O    7-NO.sub.2                                14       Cl       Cl    H      O    5-OC.sub.2 H.sub.5                        15       Cl       Cl    H      O    5-OCHF.sub.2                              ______________________________________                                    

EXAMPLE 16 Preparation of 4-(2,6-dichlorophenoxy)-6-(N-methylcarbamoyl)coumarin ##STR16##

A solution of 4-(2,6-dichlorophenoxy)-6-hydroxycoumarin (0.5 g, 1.55mmole) in dimethyl formamide, under nitrogen, at room temperature istreated with triethylamine (0.7 mL, 5 mmole), then treated with CH₃ NCO(0.5 mL, 5.5 mmole) and allowed to stir at room temperature for about 1hour. When the reaction is complete by HPLC analysis, the reactionmixture is poured onto water and extracted with methylene chloride. Theextracts are concentrated in vacuo to give a residue. The residue iscrystallized from methylene chloride/hexane to afford the title productas white crystals, 0.38₂ (71% yield), mp 292°-299° C., identified by ¹HNMR, ¹³ CNMR and IR analyses.

EXAMPLE 17 Preparation of4-(2.6-dichlorophenoxy)-6-(methoxymethyloxy)coumarin ##STR17##

A mixture of 4-(2,6-dichlorophenoxy)-6-hydroxycoumarin (1.2 g, 32mmole), dimethoxymethane (0.565 g, 7.4 mmole), POCl₃ (0.74 g, 4.8 mmole)and dimethylformamide (0.43 g, 5.94 mmole) in toluene is heated at90°-100° C. for 4 hours, cooled to room temperature, poured onto icewater and filtered. The filtercake is dried and recrystallized fromacetonitrile/water to afford the title product, 0.45 g (38% yield), mp302°-305° C. (dec), identified by ¹ HNMR, ¹³ CNMR and IR analyses.

EXAMPLE 18 Preparation of 2-hydroxy-4,5-dimethoxyacetophenone ##STR18##

A solution of 3,4-dimethoxyphenol (0.50 g, 3.24 mmole) in acetic acid istreated with boron trifluoride etherate (1.20 ml, 9.72 mmole) at 25° C.,heated at reflux temperature until reaction is complete by thin layerchromatographic analysis, cooled to room temperature and poured onto icewater. The resultant mixture is filtered, the filtercake is washed withwater and ether and dried in vacuo to give the title product as anorange powder, 0.64 g (100% yield), identified by ¹ HNMR.

EXAMPLE 19 Preparation of 2- 4-(trifluoromethoxy)phenoxy!fumaric acid##STR19##

A mixture of 4-(trifluoromethoxy)phenol (2.75 g, 12.5 mmole) anddimethyl acetylene dicarboxylate (1.69 ml, 13.7 mmole) in dioxane istreated with benzyltrimethylammonium hydroxide (0.15 ml, 40% aqueous) atroom temperature under a nitrogen atmosphere, heated to 90°-95° C.(condensation complete by thin layer chromatographic analysis) cooled to40° C. treated with sodium hydroxide (10 ml, 20% aqueous), heated at 90°C. for 1 hour and cooled to room temperature. The reaction mixture istreated with 10% aqueous HCl to pH 7 and filtered. The filtrate isacidified to about pH 1 with HCl to afford a yellow precipitate. Thesolid is filtered and dried to give the title product, 2.56 g (70%yield), mp 208°-210° C., identified by ¹ H, ¹³ C and ¹⁹ FNMR, massspectral and elemental analyses.

EXAMPLE 20 Preparation of 6-(trifluoromethoxy)chromone-2-carboxylic acid##STR20##

A solution of phosphorous pentoxide (1.17 g, 8.21 mmole) inmethanesulfonic acid (14.38 g) is treated with 2-4-(trifluoromethoxy)phenoxy!fumaric acid (2.00 g, 6.85 mmole), stirredfor 16-18 hours at ambient temperatures and for 7 hours at 70° C.,cooled to room temperature and poured onto ice. The resultant mixture isfiltered and the filtercake is dried to afford the title product, 1.75g, (93% yield), mp 192°-194° C., identified by ¹ H and ¹³ CNMR, IR, massspectral and elemental analyses.

EXAMPLE 21 Preparation of 4-chloro-6-(trifluoromethoxy)coumarin##STR21##

A stirred mixture of 6-(trifluoromethoxy)chromone-2-carboxylic acid(1.50 g, 5.47 mmole) in thionyl chloride (6.0 ml) is treated with 1 dropof dimethyl formamide (DMF), heated at reflux temperature for 6 hours,cooled to room temperature and concentrated in vacuo. The residue isdispersed in toluene, treated with a saturated NaHCO₃ solution andstirred until neutralized. The phases are separated and the toluenephase is concentrated in vacuo. The resultant residue is purified inacetonitrile and methylene chloride to give the title product, 1.04 g,(72% yield), mp 85°-87° C., identified by ¹ H, ¹³ C and ¹⁹ FNMR, IR,mass spectral and elemental analyses.

EXAMPLE 22-95 Preparation of 4-(2,6-substituted-phenoxy)coumarinderivatives

Using essentially the same procedures described in Examples 1 through21, the following 4-(2,6-disubstituted-phenoxy)coumarin derivativesshown in Table II are obtained.

                                      TABLE II                                    __________________________________________________________________________     ##STR22##                                                                    Example                                                                       No.  X    X'     R     W Y R.sub.1    mp °C.                           __________________________________________________________________________     22  Cl   Cl     H     O O H          159                                      23  F    F      H     O O H            195.6                                  24  Br   Br     H     O O H          162-170                                  25  CH.sub.3                                                                           CH.sub.3                                                                             H     O O H          163-164                                  26  F    OCH.sub.3                                                                            H     O O H          145-146                                  27  F    NO.sub.2                                                                             H     O O H          203-205                                  28  OCH.sub.3                                                                          OCH.sub.3                                                                            H     O O H          175                                      29  Cl   Cl     H     O O 6-(2Cl, 4CF.sub.3,6FC.sub.6 H.sub.2)                                                     155-157                                  30  Cl   Cl     H     O O 6-CH.sub.3 191-192                                  31  Br   Br     H     O O 6-OCH.sub.3                                                                              174-175                                  32  Br   Br     H     O O 6-CH.sub.3 182-183                                  33  Cl   Cl     H     O O 6-(OCONHC.sub.2 H.sub.5)                                                                 220-221                                  34  OCH.sub.3                                                                          OCH.sub.3                                                                            H     O O 6-OCH3     206-208                                  35  Cl   Cl     H     O O 7-OCH3     165-168                                  36  OCH.sub.3                                                                          OCH.sub.3                                                                            H     O O 7-OCH3     205.5-207                                37  OCH.sub.3                                                                          OCH.sub.3                                                                            H     O O 5-OCH3     186.5-188.5                              38  Cl   Cl     H     O O 7-(OCH.sub.2 CHCH.sub.2)                                                                 185.5-182                                39  Cl   Cl     H     O O 5-(OCH.sub.2 CHCH.sub.2)                                                                 156.5-158.5                              40  Cl   Cl     H     O O 5-(OCH.sub.2 COOCH)                                                                      161.2-162.6                              41  Cl   Cl     H     O O 6-(OCH.sub.2 COOCH)                                                                      135-136                                  42  Cl   Cl     H     O O 6-(OCH.sub.2 CHCH.sub.2)                                                                 145-146                                  43  Cl   Cl     H     O O 6-(OCH.sub.2 C CH)                                                                       153                                      44  Cl   Cl     H     O O 6-(OCH.sub.2 CH.sub.2 CFCF.sub.2)                                                        146                                      45  Cl   Cl     H     O O 6-OCH(CH.sub.3).sub.2                                                                    141                                      46  Cl   Cl     H     O O 6-OCH(CH.sub.3)C.sub.2 H.sub.5                                                           138                                      47  Cl   Cl     H     S O 6-OCH.sub.3                                                                              216-217                                  48  Cl   Cl     H     O O 6-OSO.sub.2 CF.sub.3                                                                     137                                      49  Br   Br     H     O O 6-F        165                                      50  Cl   Cl     H     O O 6-C.sub.2 H.sub.5                                                                        184                                      51  Cl   Cl     H     O O 6-F        183                                      52  Cl   Cl     H     S O 6-F        168                                      53  Cl   Cl     H     S O 6-C.sub.2 H.sub.5                                                                        182                                      54  Cl   Cl     4-Cl  O O 6,7-di-CH.sub.3                                                                          264                                      55  Br   Br     H     O O 6,7-di-OCH.sub.3                                                                         191                                      56  Cl   Cl     4-F   O O 6-OCH.sub.3                                                                              217                                      57  Cl   Cl     H     O O 6-Cl       204                                      58  Br   Br     H     O O 6-Cl       188                                      59  Cl   Cl     H     S O 6-Cl       214                                      60  Cl   Cl     4-Cl  O O 6-OCH.sub.3                                                                              196                                      61  Cl   Cl     4-F   O O 6,7-di-CH.sub.3                                                                          255                                      62  Cl   Cl     H     O O 6-OCH.sub.2 CHF.sub.2                                                                    167                                      63  Cl   Cl     H     O O 6,7-di-CH.sub.3                                                                          212                                      64  Cl   Cl     H     S O 6,7-di-CH.sub.3                                                                          246                                      65  Cl   Cl     H     O O 6,7-di-OCH.sub.3                                                                         191                                      66  Cl   Cl     H     S O 6,7-di-OCH.sub.3                                                                         172                                      67  Cl   Cl     H     O O 6,8-di-Cl  206                                      68  Cl   Cl     H     S O H          212                                      69  Br   Br     H     O O 6-C.sub.2 H.sub.5                                                                        159                                      70  Br   Br     H     O O 6,7-di-CH.sub.3                                                                          210                                      71  Br   Br     H     O O 6,8-di-Cl  218                                      72  Cl   Cl     4-F   O O 6-F        187                                      73  Cl   Cl     4-Cl  O O 6-F        208                                      74  Cl   Cl     4-F   O O 6,7-di-OCH.sub.3                                                                         205                                      75  Cl   Cl     4-Cl  O O 6-Cl       221                                      76  Cl   Cl     4-F   O O 6-Cl       200                                      77  Cl   Cl     H     O O 6-OC.sub.2 H.sub.5                                                                       162                                      78  F    F      3,4,5-tri-F                                                                         O O 6-F        173                                      79  Br   Br     4-CH.sub.3                                                                          O O 6,7-di-OCH.sub.3                                                                         154                                      80  Cl   Cl     H     O O 6-OCH.sub.2 C.sub.6 H.sub.4 OCF.sub.3 -p                                                 129                                      81  Br   Br     4-F   O O 6-OCH.sub.3                                                                              200                                      82  Br   Br     4-Br  O O 6-OCH.sub.3                                                                              195-197                                  83  Cl   Cl     3-Cl  O O 6-OCH.sub.3                                                                              218-220                                  84  F    F      H     O O 6-OCH.sub.3                                                                              213-214                                  85  Cl   Cl     H     O O 6-CN       249-250                                  86  Cl   Cl     H     O O 5,6,7-tri-OCH.sub.3                                                                      169-170                                  87  Cl   Cl     H     O O 5-OCH.sub.3                                                                              203.6-207.5                              88  Cl   Cl     H     O O 7-OH         263-264.5                              89  Cl   Cl     H     O O 5-OH       250-256                                  90  Cl   Cl     H     S O 5-OCH.sub.3                                                                              204-205                                  91  Br   Br     H     O O 5-OCH.sub.3                                                                              201-203                                  92  Cl   Cl     H     S O 8-OCH.sub.3                                                                              183-185                                  93  Br   Br     H     O O 8-OCH.sub.3                                                                              157                                      94  Cl   Cl     H     O O 8-OCH.sub.3                                                                              142-144                                  95  Br   Br     H     O O 5,6,7-tri-OCH.sub.3                                                                      179-181                                  99  Br   Br     H     O O 6-OH       210                                     100  Cl   Cl     H     O O 6-I        266-267                                 101  Br   Br     H     O O 6-OCHF.sub.2                                                                             151-152                                 102  Cl   Cl     H     O O 8-OCHF.sub.2                                                                             198-201                                 103  Br   Br     H     O O 8-OCHF.sub.2                                                                             181-183                                 104  Cl   Cl     H     O O 6-CH.sub.2 OCH.sub.3                                                                     158                                     105  Br   Br     H     O O 8-OH       227                                     106  Cl   Cl     H     O O 8-OH       252                                     107  CH.sub.3                                                                           CH.sub.2 CHCH.sub.2                                                                  H     O O 6-OCH.sub.3                                                                              88-90                                   108  CH(CH.sub.3).sub.2                                                                 CH(CH.sub.3).sub.2                                                                   H     O O 6-OCH.sub.3                                                                              129-131                                 109  CH.sub.3                                                                           CH.sub.3                                                                             H     O O 6-OCH.sub.3                                                                              192-193                                 110  Cl   Cl     H     O O 6-OCF.sub.3                                                                              172-175                                 111  Cl   Cl     H     O O 6-CF.sub.3 181-183                                 112  Br   Br     H     O O 6-CH.sub.2 Br                                                                            220                                     113  Cl   Cl     H     O O 6-CHO      200                                     114  CH.sub.3                                                                           C(CH.sub.3).sub.3                                                                    H     O O 6-OCH.sub.3                                                                              148-151                                 115  Cl   Cl     H     O O 6-C.sub.6 H.sub.5                                                                        146-152                                 116  Cl   Cl     H     O O 6-COOH     305                                     117  Br   Br     H     O O 6-CHO      185-197                                 118  Cl   Cl     H     O O 6-OCH.sub.2 CH.sub.2 OC.sub.2 H.sub.5                                                    89-91                                   119  Cl   Cl     H     O O 6-SCH.sub.3                                                                              168-170                                 120  Cl   CH.sub.3                                                                             H     O O 6-OCH.sub.3                                                                              192                                     121  Cl   CH.sub.3                                                                             H     O O 6.7-di-OCH.sub.3                                                                         141                                     122  Cl   CH.sub.3                                                                             H     O O 6,7-di-OCH.sub.3                                                                         172-173                                 123  Cl   CH.sub.3                                                                             H     O O 6-CH.sub.3 186                                     124  Cl   CH.sub.3                                                                             H     O O 6-C.sub.2 H.sub.5                                                                        165-166                                 125  Cl   CH.sub.3                                                                             H     O O 8-OCH.sub.3                                                                              157-158                                 126  CH.sub.3                                                                           CH.sub.3                                                                             H     O O 8-OCH.sub.3                                                                              142-143                                 127  Cl   Cl     H     O O 6,7-di-OH  >300                                    128  CH.sub.3                                                                           n-C.sub.3 H.sub.7                                                                    H     O O 6-OCH.sub.3                                                                              --                                      129  CH.sub.3                                                                           CH.sub.3                                                                             H     O O 6-CF.sub.3 193-194                                 130  CH.sub.3                                                                           CH.sub.3                                                                             H     O O 6-OCF.sub.3                                                                              162-164                                 131  Cl   CH.sub.3                                                                             H     O O 8-CF.sub.3 205-206                                 132  Br   Br     3,5-di-OCH.sub.3                                                                    O O 6-OCH.sub.3                                                                              233-234                                 133  Cl   CH.sub.3                                                                             H     O O 5,6,7-tri-OCH.sub.3                                                                      143-144                                 134  I    I      4-I   O O 6-OCH.sub.3                                                                              202-203                                 135  Cl   Cl     H     O O 8-CF.sub.3 217-218                                 136  Cl   CH.sub.3                                                                             H     O O 5-OCH.sub.3                                                                              172-173                                 137  Cl   Cl     H     O O 5-CF.sub.3 159-160                                 138  Br   Br     H     O O 5-CF.sub.3 179-189                                 139  Cl   CH.sub.3                                                                             H     O O 5-CF.sub.3 157-159                                 140  Cl   CH.sub.3                                                                             H     O O 6-Cl,7-OCH.sub.3                                                                         167-168                                 141  Br   CH.sub.3                                                                             H     O O 6-OCH.sub.3                                                                              180-181                                 142  Cl   Cl     H     O O 6-C CH     220-224                                 143  Cl   CH.sub.3                                                                             H     O O 8-CH.sub.3 174-175                                 144  Cl   Cl     H     O O 7-OCHF.sub.2                                                                             158-160                                 145  Cl   CH.sub.3                                                                             H     O O 6-OCHF.sub.2                                                                             158-161                                 146  Cl   Cl     H     O O 7-CF.sub.3 180-181                                 147  Cl   CH.sub.3                                                                             H     O O 7-CF.sub.3 146-148                                 148  Cl   CH.sub.3                                                                             H     O O 7,8-di-OCH.sub.3                                                                           179-181.5                             149  Cl   Cl     H     O O 5-OCH(CH.sub.3).sub.2                                                                    158.5-162                               150  Cl   Cl     H     O O 5-OC.sub.2 H.sub.5                                                                       152.5-155                               151  Cl   Cl     H     O O 5-OCHF.sub.2                                                                             178.3-180                               152  Cl   Cl     H     O O 5-OCH.sub.3,6-Cl                                                                         176-178                                 153  Cl   Cl     H     O O 8-Cl       206-208                                 154  Cl   Cl     H     O O 5-OCOCH.sub.3                                                                            130-133                                 155  Cl   CH.sub.3                                                                             H     O O 5-Cl       135-136                                 156  Br   Br     H     O O 5-Cl       155-156                                 157  Cl   Cl     H     O O 5-Cl       157-158                                 158  Cl   Cl     H     O O 5-OCH.sub.3,8-Cl                                                                           213-215.5                             159  Cl   CH.sub.3                                                                             H     O O 5-CH.sub.3,8-Cl                                                                          175-176                                 160  Cl   Cl     H     O O 5-CH.sub.3,8-Cl                                                                          166-167                                 161  Cl   Cl     H     O O 5-OCOC(CH.sub.3).sub.3                                                                   139-141                                 162  Br   Br     H     O O 5-OCOCH.sub.3                                                                            220-223                                 163  Br   Br     H     O O 5-OCOC(CH.sub.3).sub.3                                                                   218.3-220                               164  Cl   Cl     H     O O 7-OCOCH.sub.3                                                                              182-183.5                             165  Cl   Cl     H     O O 7-OCOC(CH.sub.3).sub.3                                                                   135-137                                 166  Cl   Cl     H     O O 8-OCOCH.sub.3                                                                            161-163                                 167  Cl   Cl     H     O O 8-OCOC(CH.sub.3).sub.3                                                                   144-146                                 168  Cl   Cl     H     O O 5-F        146-147                                 169  Cl   CH.sub.3                                                                             H     O O 5-F        137-138                                 170  Cl   Cl     H     O O 5-CH.sub.3 129-130                                 171  Cl   CH.sub.3                                                                             H     O O 5-CH.sub.3 118-119                                 172  Cl   Cl     H     O O 5.7-di-Cl  205-207                                 173  Br   Br     H     O O 5,7-di-Cl  208-209                                 174  Cl   CH.sub.3                                                                             H     O O 5,7-di-Cl  158-160                                 175  Cl   Cl     H     O O 6,7-di-Cl  195-196                                 176  Cl   Cl     H     O O 5,6-di-Cl  193-195                                 177  Cl   CH.sub.3                                                                             H     O O 6,7-di-Cl  210-212                                 178  Br   Br     H     O O 6,7-di-CH.sub.3                                                                          155-156                                 179  Br   Br     H     O O 5,6-di-Cl  209-211                                 180  Br   Br     H     O O 6,7-di-Cl  206-208                                 181  Cl   Cl     H     O O 5,7-di-CH.sub.3,6-Cl                                                                     210-212                                 182  Br   Br     H     O O 5,7-di-CH.sub.3,6-Cl                                                                     219-221                                 183  Cl   CH.sub.3                                                                             H     O O 5,7-di-CH.sub.3,6-Cl                                                                     187-188                                 184  Cl   Cl     H     O O 7,8-di-Cl  212-214                                 185  Br   Br     H     O O 7,8-di-Cl  211-212                                 186  Cl   CH.sub.3                                                                             H     O O 7,8-di-Cl  234-236                                 187  Cl   Cl     H     O O 5,7-di-Br,6-CH.sub.3                                                                     217-218                                 188  Cl   CH.sub.3                                                                             H     O O 5,7-di-Br,6-CH.sub.3                                                                     201-203                                 189  Cl   Cl     H     O O 5,8-di-Cl  190-191                                 190  Br   Br     H     O O 5,8-di-Cl  203-205                                 191  Cl   CH.sub.3                                                                             H     O O 5,8-di-Cl  181-183                                 192  Cl   Cl     H     O O 5-NO.sub.2 211-212                                 __________________________________________________________________________

EXAMPLE 193 Preparation of 4-hydroxy-5-(trifluoromethyl)dithiocoumarin##STR23##

A mixture of 2'-fluoro-6'-(trifluoro-methyl)acetophenone (3.0 g, 14.5mmol), carbon disulfide (1.5 mL, 26.7 mmol) and dimethylformamide (DMF)(12.5 mL) in benzene at 15°-25° C. is treated portion-wise with a 60%dispersion of sodium hydride in mineral oil (1.15 g, 28.8 mmol NaH) overa 1.5 hour period, stirred for 0.5 hour, heated at 125° C. for 1 hour,cooled to room temperature and diluted with water. The resultant mixtureis treated with acetic acid and extracted with ether. The aqueous phaseis acidified to pH 3 with HCl and extracted with ethyl acetate. Theethyl acetate extracts are combined, washed sequentially with water andbrine, dried over MgSO₄ and concentrated in vacuo to give an orange oilresidue. The residue is crystallized from diethyl ether/hexanes to givethe title product as a white solid, 3.0 g (79% y), mp 142°-144° C.,identified by IR, ¹ HNMR, ¹⁹ FNMR and mass spectral analyses.

EXAMPLE 194 Preparation of4-(2,6-dichlorophenoxy)-5-trifluoromethyl)dithiocoumarin ##STR24##

Using essentially the same procedures described in Examples 3 and 4hereinabove, the title product is obtained and identified by IR, ¹ HNMR,¹⁹ FNMR and mass spectral analyses.

EXAMPLE 195 Preparation of4-(2,6-dichlorophenoxy)-6-chlorodithiocoumarin. ##STR25##

Using essentially the same procedures described hereinabove in Examples3, 4 and 193, the title product is obtained, mp 208°-210° C., identifiedby IR, ¹ HNMR and mass spectral analyses.

EXAMPLE 196 Preemergence Herbicidal Evaluation Of Test Compounds In ThePresence of Transplanted Rice Under Flooded Paddy Conditions

The preemergence herbicidal activity and rice crop tolerance underpost-transplant application conditions is determined in the followingmanner. Grass weed seeds or tubers are planted in the top 0.5 cm of siltloam soil in plastic containers with no drainage holes and 4-6 riceseedlings (CV. Tebonnet), at the two-leaf stage, are transplanted intothe same containers. The plastic containers may be 32 oz. containershaving a diameter of 10.5 cm or 13 cm×13 cm square by 8 cm deep. Afterseeding and transplanting, the containers are placed on greenhousebenches and the soil is kept saturated for 3 days. On the 3rd day, thecontainers are flooded to a level of 2-3 cm of water above the soilsurface. The flooded soil surface is then treated with selected aqueousacetone (20/80 v/v water/acetone) mixtures and sufficient test compoundto provide the equivalent of about 4.0 kg/ha to 0.50 kg/ha of activeingredient. After treatment, the containers are kept on greenhousebenches and watered such that the water level is maintained at 2-3 cmabove the soil surface.

Three to four weeks after treatment, the plants are evaluated and ratedfor herbicidal effect based on visual determination of stand, size,vigor, chlorosis, growth malformation and overall appearance. The ratingsystem used is shown below. If more than one test is run, the data areaveraged. The results are reported in Table III.

    ______________________________________                                        RATING SYSTEM USED                                                                                     % Control                                            Rating   Meaning         Compard to Check                                     ______________________________________                                        0        No Effect       0                                                    1        Trace Effect    1-5                                                  2        Slight Effect    6-15                                                3        Moderate Effect 16-29                                                4        Injury          30-44                                                5        Definite Injury 45-64                                                6        Herbicidal Effect                                                                             65-79                                                7        Good Herbicidal Effect                                                                        80-90                                                8        Approaching Complete Kill                                                                     91-99                                                9        Complete Kill   100                                                  --       Not Tested                                                           ______________________________________                                        PLANT SPECIES USED                                                            Abbreviation                                                                              Common Name  Scientific Name                                      ______________________________________                                        ECHCG       Barnyard Grass                                                                             Echinochloa crus-galli                                                        (L.) Beauv.                                          ECHORC      Water Grass  Echinochloa oryzoides                                                         (ARD.) Fritsch                                       ORYSAT      Rice, Tebonnet                                                                             Oryza sativa, L.                                                              CV. Tebonnet                                         ______________________________________                                    

                  TABLE III                                                       ______________________________________                                        PREEMERGENCE/POST-TRANSPLANT EVALUATION                                       Example   Rate                                                                No.       kg/ha  ECHCG      ECHORC ORYSAT                                     ______________________________________                                         8        2.0    9.0        --     0.0                                                  1.0    9.0        9.0    0.3                                                  0.5    9.0        9.0    0.3                                         9        1.0    9.0        --     1.5                                                  0.5    9.0        --     1.5                                        10        1.0    9.0        9.0    0.0                                                  0.5    9.0        9.0    0.0                                        12        1.0    --         9.0    0.0                                                  0.5    --         8.0    0.0                                        21        1.0    8.0        --     0.0                                                  0.5    --         8.0    0.0                                        22        1.0    9.0        --     0.5                                                  0.5    9.0        --     0.5                                        23        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        24        1.0    9.0        --     2.0                                                  0.5    9.0        --     2.0                                        25        1.0    --         6.0    0.0                                                  0.5    --         2.0    0.0                                        29        1.0    7.0        --     3.0                                                  0.5    7.0        --     2.0                                        30        1.0    9.0        --     0.5                                                  0.5    9.0        --     0.3                                        31        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        32        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        33        1.0    0.0        --     0.0                                                  0.5    9.0        --     0.0                                        34        4.0    9.0        --     0.0                                                  1.0    9.0        9.0    0.0                                                  0.5    9.0        7.0    0.0                                        38        1.0    8.0        --     0.0                                                  0.5    7.0        --     0.0                                        39        1.0    7.0        --     0.0                                                  0.5    7.0        --     0.0                                        40        1.0    9.0        --     0.0                                                  0.5    6.0        --     0.0                                        41        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        42        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        43        1.0    8.0        --     1.0                                                  0.5    7.0        --     0.0                                        44        1.0    9.0        --     0.0                                                  0.5    7.0        --     0.0                                        45        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        46        1.0    1.0        --     0.0                                                  0.5    0.0        --     0.0                                        47        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        48        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        49        1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        50        1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        51        1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        52        4.0    3.0        --     0.0                                                  1.0    7.0        0.0    0.0                                                  0.5    2.0        0.0    0.0                                        53        4.0    0.0        --     0.0                                                  1.0    2.0        --     0.0                                                  0.5    1.0        --     0.0                                        54        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        55        1.0    9.0        9.0    0.0                                                  0.5    9.0        9.0    0.0                                        56        1.0    9.0        --     0.0                                                  0.5    8.0        --     0.0                                        57        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        58        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        59        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        60        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        61        1.0    2.0        --     0.0                                                  0.5    1.0        --     0.0                                        62        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        63        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        64        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        65        1.0    9.0        9.0    0.0                                                  0.5    9.0        9.0    0.0                                        66        1.0    7.0        --     0.0                                                  0.5    1.0        --     0.0                                        67        1.0    9.0        --     0.0                                                  0.5    6.0        --     0.0                                        68        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        69        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        70        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        71        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        72        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        73        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        74        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        75        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        76        1.0    4.0        --     0.0                                                  0.5    2.0        --     0.0                                        77        1.0    0.0        --     0.0                                                  0.5    0.0        --     0.0                                        78        1.0    --         0.0    0.0                                                  0.5    --         0.0    0.0                                        79        1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        80        1.0    --         0.0    0.0                                                  0.5    --         0.0    0.0                                        81        1.0    --         0.0    0.0                                                  0.5    --         0.0    0.0                                        82        1.0    --         9.0    0.0                                                  0.5    --         8.0    0.0                                        83        1.0    --         0.0    0.0                                                  0.5    --         0.0    0.0                                        84        1.0    --         6.0    0.0                                                  0.5    --         1.0    0.0                                        85        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        86        1.0    9.0        9.0    0.0                                                  0.5    9.0        9.0    0.0                                        87        4.0    9.0        --     0.0                                                  1.0    9.0        9.0    0.0                                                  0.5    9.0        9.0    0.0                                        88        1.0    7.0        --     0.0                                                  0.5    6.0        --     0.0                                        89        1.0    6.0        --     0.0                                                  0.5    6.0        --     0.0                                        90        1.0    4.5        --     0.0                                                  0.5    3.5        --     0.0                                        91        1.0    9.0        --     0.0                                                  0.5    9.0        --     0.0                                        92        1.0    2.0        --     0.0                                                  0.5    2.0        --     0.0                                        93        1.0    9.0        --     0.0                                                  0.5    9.0        9.0    0.0                                        94        1.0    9.0        --     0.0                                                  0.5    9.0        9.0    0.0                                        95        1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        101       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        110       1.0    --         8.5    0.0                                                  0.5    --         8.0    0.0                                        111       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        114       2.0    --         0.0    0.0                                                  1.0    --         0.0    0.0                                                  0.5    --         0.0    0.0                                        116       1.0    --         5.5    0.0                                                  0.5    --         1.5    0.0                                        117       2.0    --         7.0    4.0                                                  1.0    --         7.0    3.0                                                  0.5    --         3.0    0.5                                        121       1.0    --         9.0    2.0                                                  0.5    --         9.0    1.0                                        122       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        127       1.0    --         0.0    0.0                                                  0.5    --         0.0    0.0                                        133       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        136       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.5                                        137       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.2                                        138       2.0    --         9.0    4.0                                                  1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        139       1.0    --         9.0    0.0                                                  0.5    --         0.0    0.0                                        148       1.0    --         0.0    0.0                                                  0.5    --         0.0    0.0                                        155       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        156       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        157       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        172       1.0    --         9.0    0.0                                                  0.5    --         8.5    0.0                                        173       1.0    --         8.0    0.0                                                  0.5    --         8.0    0.0                                        174       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        175       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        176       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        177       1.0    --         7.0    0.0                                                  0.5    --         5.5    0.0                                        192       1.0    --         9.0    0.0                                                  0.5    --         9.0    0.0                                        ______________________________________                                    

EXAMPLE 197 Preemergence Herbicidal Evaluation Of Test Compounds In ThePresence Of Transplanted Rice Under Flooded Paddy Conditions

In this example, Deluvian paddy soil (Toyokawa paddy soil) is placed inplastic pots, 100 cm² ×9 cm in depth. Water is added to the level of thesoil surface in the pot and the mixture is paddled 3 cm in depth.

Pots are then variously sown with monocotyledenous weed seeds and tubersat 0-2 cm in soil depth, as well as transplanted rice plants at the 2.5leaf stage. The rice plants are transplanted at about 3 cm soil depth.Water is then added to all of the pots to 3 cm deep and kept at a depthof 3 cm for the duration of the test. Test compounds are applied in themanner described in Example 96 two days after transplanting the riceplants and sowing the weed seeds and tubers. The pots are then placed ongreenhouse benches and cared for in the conventional manner. Tests areevaluated at 20 and 30 days after treatment. Evaluations made at 30 daysafter treatment are shown on Table IV. The rating system used is thesame as that described in Example 196.

    ______________________________________                                        PLANT SPECIES USED                                                            Abbreviation                                                                             Common Name    Scientific Name                                     ______________________________________                                        ECHCG      Barnyard Grass Echinochloa crus-galli                              SAGPY      Arrowhead (Pygmaea)                                                                          Sagittaria pygmaea                                  CYPSE      Flatsedge,     Cyperus serotinus                                              perennial                                                          MOOVA      Monochoria     Monochloria vaginalis                               CYPDI      Flatsedge,     Cyperus difformis                                              smallflower                                                        SCPJU      Bulrush, Japanese                                                                            Scirpus juncoides                                   ORYSAK     Rice, Koshihikari                                                                            Oryza sativa, L.                                                              CV. Koshihikari                                     ______________________________________                                    

                                      TABLE IV                                    __________________________________________________________________________    PREEMERGENCE/POST-TRANSPLANT EVALUATION                                       Ex.                                                                              Rate                                                                       No.                                                                              kg/ha                                                                            ECHCG                                                                             SAGPY                                                                             CYPSE                                                                             MOOVA                                                                              CYPDI                                                                             SCPJU                                                                             ORYSAK                                         __________________________________________________________________________     8 1.0                                                                              9   2   2   9    9   8   0                                                 0.5                                                                              9   1   0   9    9   7   0                                               9 1.0                                                                              7   0   0   1    2   0   0                                                 0.5                                                                              6   0   0   0    0   0   0                                              10 1.0                                                                              9   2   0   9    9   5   0                                                 0.5                                                                              9   0   0   8    9   4   0                                              12 1.0                                                                              9   0   0   7    3   0   0                                                 0.5                                                                              9   0   0   6    2   0   0                                              21 1.0                                                                              8   0   7   3    5   0   0                                                 0.5                                                                              7   0   2   0    3   0   0                                              22 1.0                                                                              9   1   1   9    8   7   0                                                 0.5                                                                              9   0   0   8    7   5   0                                              23 2.0                                                                              9   0   0   3    2   2   0                                                 1.0                                                                              6   0   0   0    0   0   0                                                 0.5                                                                              4   0   0   0    0   0   0                                              25 1.0                                                                              9   0   0   3    2   2   0                                                 0.5                                                                              9   0   0   8    3   0   0                                              31 1.0                                                                              9   0   4   7    7   3   0                                                 0.5                                                                              9   0   0   7    6   0   0                                              32 1.0                                                                              9   0   2   8    8   2   0                                                 0.5                                                                              9   0   1   7    7   0   0                                              33 2.0                                                                              6   9   9   9    9   7   8                                                 1.0                                                                              4   8   9   9    9   6   8                                                 0.5                                                                              2   7   9   9    8   5   5                                              35 2.0                                                                              8   2   0   0    1   0   0                                                 1.0                                                                              8   0   0   0    0   0   0                                                 0.5                                                                              7   0   0   0    0   0   0                                              38 1.0                                                                              8   0   0   0    0   0   0                                                 0.5                                                                              6   0   0   0    0   0   0                                              39 1.0                                                                              7   0   0   0    0   0   0                                                 0.5                                                                              5   0   0   0    0   0   0                                              40 1.0                                                                              9   0   0   0    0   0   0                                                 0.5                                                                              9   0   0   0    0   0   0                                              41 1.0                                                                              9   1   7   8    9   2   1                                                 0.5                                                                              9   0   3   7    7   1   0                                              42 2.0                                                                              2   0   0   0    0   0   0                                                 1.0                                                                              0   0   0   0    0   0   0                                                 0.5                                                                              0   0   0   0    0   0   0                                              43 1.0                                                                              8   0   0   0    0   0   0                                                 0.5                                                                              6   0   0   0    0   0   0                                              44 1.0                                                                              8   0   0   0    0   0   0                                                 0.5                                                                              5   0   0   0    0   0   0                                              45 1.0                                                                              8   0   0   0    0   0   0                                                 0.5                                                                              5   0   0   0    0   0   0                                              46 2.0                                                                              0   0   0   0    0   0   0                                                 1.0                                                                              0   0   0   0    0   0   0                                              47 2.0                                                                              0   0   0   0    0   0   0                                                 1.0                                                                              0   0   0   0    0   0   0                                              48 2.0                                                                              0   0   0   0    0   0   0                                                 1.0                                                                              0   0   0   0    0   0   0                                              49 1.0                                                                              9   0   5   9    9   8   0                                                 0.5                                                                              9   0   2   9    8   5   0                                              50 1.0                                                                              9   0   0   8    8   1   0                                                 0.5                                                                              9   0   0   8    7   0   0                                              51 1.0                                                                              9   0   2   8    7   0   0                                                 0.5                                                                              8   0   0   8    5   0   0                                              55 1.0                                                                              9   1   9   9    9   9   0                                                 0.5                                                                              9   0   8   9    9   8   0                                              56 1.0                                                                              8   0   0   3    2   0   0                                                 0.5                                                                              6   0   0   2    1   0   0                                              57 1.0                                                                              9   0   2   2    2   0   0                                                 0.5                                                                              9   0   0   1    1   0   0                                              58 1.0                                                                              9   0   0   4    3   0   0                                                 0.5                                                                              9   0   0   2    1   0   0                                              59 1.0                                                                              5   0   0   1    2   2   0                                                 0.5                                                                              3   0   0   0    0   0   0                                              60 1.0                                                                              9   0   5   6    5   0   0                                                 0.5                                                                              9   0   0   5    3   0   0                                              61 1.0                                                                              4   0   0   1    1   0   0                                                 0.5                                                                              3   0   0   0    0   0   0                                              62 1.0                                                                              2   0   0   0    0   0   0                                                 0.5                                                                              0   0   0   0    0   0   0                                              63 1.0                                                                              9   0   0   2    1   1   0                                                 0.5                                                                              9   0   0   1    0   0   0                                              64 1.0                                                                              1   0   0   0    0   0   0                                                 0.5                                                                              0   0   0   0    0   0   0                                              65 1.0                                                                              9   4   5   9    9   2   1                                                 0.5                                                                              9   2   2   9    9   0   0                                              66 1.0                                                                              9   0   0   2    2   0   0                                                 0.5                                                                              8   0   0   0    0   0   0                                              67 1.0                                                                              9   0   1   2    3   0   1                                                 0.5                                                                              8   0   0   0    2   0   0                                              68 1.0                                                                              0   0   0   0    0   0   0                                                 0.5                                                                              0   0   0   0    0   0   0                                              69 1.0                                                                              9   0   2   7    7   2   1                                                 0.5                                                                              9   0   0   6    6   0   0                                              70 1.0                                                                              9   0   5   2    1   0   0                                                 0.5                                                                              9   0   0   0    0   0   0                                              71 1.0                                                                              6   0   0   0    0   0   0                                                 0.5                                                                              5   0   0   0    0   0   0                                              72 1.0                                                                              9   0   1   7    4   0   0                                                 0.5                                                                              9   0   0   3    2   0   0                                              73 1.0                                                                              7   0   2   0    0   0   0                                                 0.5                                                                              3   0   0   0    0   0   0                                              74 1.0                                                                              9   0   0   4    6   2   0                                                 0.5                                                                              9   0   0   2    3   0   0                                              75 1.0                                                                              4   0   0   2    1   0   0                                                 0.5                                                                              2   0   0   0    0   0   0                                              76 1.0                                                                              7   0   0   2    1   1   0                                                 0.5                                                                              6   0   0   0    0   0   0                                              77 1.0                                                                              6   0   0   2    0   0   0                                                 0.5                                                                              6   0   0   1    0   0   0                                              78 1.0                                                                              2   1   4   2    0   6   0                                                 0.5                                                                              0   0   2   1    0   4   0                                              79 1.0                                                                              9   2   0   9    9   7   0                                                 0.5                                                                              9   1   0   8    7   6   0                                              85 1.0                                                                              9   0   0   4    4   2   0                                                 0.5                                                                              7   0   0   1    2   1   0                                              86 1.0                                                                              9   5   5   9    9   9   0                                                 0.5                                                                              9   2   2   9    9   8   0                                              87 1.0                                                                              9   0   4   8    8   4   0                                                 0.5                                                                              9   0   2   7    8   2   0                                              88 1.0                                                                              5   0   0   0    0   0   0                                                 0.5                                                                              4   0   0   0    0   0   0                                              89 1.0                                                                              4   0   0   0    0   0   0                                                 0.5                                                                              2   0   0   0    0   0   0                                              90 1.0                                                                              3   0   0   0    0   0   0                                                 0.5                                                                              0   0   0   0    0   0   0                                              91 1.0                                                                              9   0   0   5    8   0   0                                                 0.5                                                                              9   0   0   3    5   0   0                                              93 1.0                                                                              9   0   2   9    9   7   0                                                 0.5                                                                              9   0   0   8    8   5   0                                              94 1.0                                                                              9   0   7   9    9   8   0                                                 0.5                                                                              9   0   3   9    9   5   0                                              116                                                                              0.50                                                                             7   6   3   2    8   6   0                                                 0.25                                                                             5   4   1   0    7   5   0                                              117                                                                              0.50                                                                             7   2   5   4    8   7   1                                                 0.25                                                                             5   1   2   0    7   6   1                                              119                                                                              0.50                                                                             9   2   0   0    2   0   0                                                 0.25                                                                             8   0   0   0    1   0   0                                              120                                                                              0.50                                                                             9   0   --  6    9   8   0                                                 0.25                                                                             9   0   --  2    9   7   0                                              121                                                                              0.50                                                                             9   0   3   5    9   8   0                                                 0.25                                                                             9   0   0   2    9   6   0                                              122                                                                              0.50                                                                             9   4   0   0    9   5   0                                                 0.25                                                                             9   2   0   0    9   3   0                                              123                                                                              0.50                                                                             9   0   0   0    9   7   0                                                 0.25                                                                             9   0   0   0    7   5   0                                              124                                                                              0.50                                                                             9   2   0   0    9   7   0                                                 0.25                                                                             9   0   0   0    9   6   0                                              125                                                                              0.50                                                                             9   0   2   5    9   9   0                                                 0.25                                                                             9   0   0   2    9   6   0                                              126                                                                              0.50                                                                             9   2   --  3    7   6   0                                                 0.25                                                                             9   2   --  2    3   2   0                                              136                                                                              0.50                                                                             9   0   0   2    7   5   0                                                 0.25                                                                             9   0   0   0    6   4   0                                              137                                                                              0.50                                                                             9   0   2   7    9   9   0                                                 0.25                                                                             9   0   1   7    9   9   0                                              138                                                                              0.50                                                                             9   0   0   5    9   9   0                                                 0.25                                                                             9   0   0   6    9   9   0                                              139                                                                              0.50                                                                             9   0   2   8    9   9   0                                                 0.25                                                                             9   0   2   8    9   9   0                                              155                                                                              0.50                                                                             9   0   2   9    9   9   0                                                 0.25                                                                             9   0   --  7    9   9   0                                              __________________________________________________________________________

What is claimed is:
 1. A method for preparation of a compound of formulaIa ##STR26## wherein X and X' are each independently halogen, C₁ -C₄alkyl or C₂ -C₄ alkenyl;W is O or S; R is any combination of from one tothree H, halogen, C₁ -C₄ alkyl, C₃ -C₆ cycloalkyl, C₁ -C₄ haloalkyl orC₁ -C₄ alkoxy groups; R₁ is any combination of from one to four H,halogen, OH, CN, NO₂, SH, C₁ -C₆ alkyl optionally substituted with oneor more halogen or OR₂ groups, C₃ -C₆ cycloalkyl, C₂ -C₆ alkylthio C₂-C₆ alkenyl, C₂ -C₆ halo-alkenyl, C₂ -C₆ alkynyl, C₂ -C₆ haloalknyl,OR₂, OCH₂ COOR₃, OCH₂ OR₄, OCOOR₅, OCONHR₆, OCOR₇, S(O)_(n) R₈, COR₉,CH(OR₁₀)₂, phenyl optionally substituted with one to three halogen, CN,C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy or C₁ -C₄ haloalkoxygroups, or benzyl optionally substituted with one to three halogen, CN,C₁ -C₄ alkyl, C₁ -C₄ haloalkyl or C₁ -C₄ alkoxy groups; with the provisothat at least one of R₁ must be other than H; R₂ is H, C₁ -C₄ alkyl, C₁-C₄ haloalkyl, C₂ -₆ alkenyl, C₂ -₆ alkynyl, C₂ -C₆ haloalkenyl or C₂-C₆ haloalkynyl; R₃, R₄, R₅, R₆ and R₇ are each independently H, C₁ -C₄alkyl, C₁ -C₄ haloalkyl, C₃ -C₆ cycloalkyl, phenyl optionallysubstituted with one to three halogen, CN, C₁ -C₄ alkyl, C₁ -C₄haloalkyl, C₁ -C₄ alkoxy or C₁ -C₄ haloalkoxy groups, or benzyloptionally substituted with one to three halogen, C₁ -C₄ alkyl, C₁ -C₄haloalkyl or C₁ -C₄ alkoxy groups; R₈ is C₁ -C₄ alkyl, C₁ -C₄ haloalkylor phenyl optionally substituted with one to three halogen, CN, C₁ -C₄alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy or C₁ -C₄ haloalkoxy groups; R₉is H, OH, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenyl optionally substitutedwith one to three halogen, CN, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄alkoxy or C₁ -C₄ haloalkoxy groups, benzyl optionally substituted withone to three halogen, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy orC₁ -C₄ haloalkoxy groups or NR₁₁ R₁₂ ; R₁₀ is H, C₁ -C₄ alkyl or--(CH₂)_(m) --; R₁₁ and R₁₂ are each independently H, C₁ -C₄ alkyl, C₂-C₄ alkenyl or R₁₁ and R₁₂ may be taken together with the atoms to whichthey are attached to form a 5- or 6-membered ring optionally interruptedby oxygen; n is an integer of 0, 1 or 2 and m is an integer of 2 or3;which comprises reacting a compound of formula V ##STR27## with atleast 1 molar equivalent of a compound of formula VI ##STR28## in thepresence of a solvent, optionally in the presence of a base.
 2. A methodfor the preparation of a compound of formula V ##STR29## wherein R₁ isas described in claim 1 which comprises cyclodehydrating a compound offormula IX ##STR30## with a mixture of phosphorous pentoxide and methanesulfonic acid to form a chromone-2-carboxylic acid intermediate andreacting the intermediate with thionyl chloride in the presence of acatalytic amount of dimethyl formamide to give the desired4-chlorocoumarin product of formula V.